Cooling system leak detector



Aug. 3, 1948. H, EATON 2,446,219

I COOLING SYSTEM LEAK DETECTOR Filed Feb. 16, 1945 4a 9 as {2 50 5/ H M A l6 ,2 E 1 .a

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hose connection 23 to the top of the radiator down through which it flows to the lower end of the radiator 20 wherein it is cooled and returns to the engine block through the housing connection 24. Circulation of the coolant liquid is also established through radiator accessories, such as a crank case heater or a car heater 26, which is illustrated at 26 in Fig. 2. The pump 22 circulates the coolant through the pipe 21, the heaters 25 and 26 and returns it to the-engine block head through the pipe 28. Accessories of this character attached to the cooling system must also be i checked for leaks.

By attaching the flexible tube ll of the leak" detector I0 to the end of the overflow pipe l9 and I tightly securing the radiator cap 29 a controlled pressure may be applied through the hose I! to the cooling system which is filled with liquid such as water or water mixed with an anti-freeze. This pressure is transmitted through the whole of the cooling system and if any part thereof is apt to leak under the pressure applied the-cooling liquid will seep or flow through the leak,=causing the pressure on the system to be quickly'reduced, which reduction in pressure is-indicated by the hand 30 on the pressure gauge I quickly returning to zero. 1 Any-suitable means'may be provided" for supplying pressure to the cooling system, such as a hand pump or the rubber pressure bulb 3|. The bulb 3| is provided with a check valve 32 at the inlet end and a connecting nipple 33fatt'he outletend. I

The T-fitting I4 is provided with a threaded opening 34 for receivingthe externally threaded valve housing 35 that forms the stem ofthe T. The bore of the valve housing 35 is provided with a sleeve 36 having a valve seat on one end thereof arranged to be engaged by the valve member 31 secured to the valve stem 38 which ismain tained on the valve seat by the valve spring 39. The outer end of the valvehou'sing i's"pr'ov'ided with a connecting nipple 40 arranged to receive the flexible rubber hose 4|, the other end of which is telescoped over the outerend of the nipple 33 secured to the pressure bulb 3|.

When the leak detector is attached to the overflow pipe I9 of the filled coolant system; fluid pressure may be exerted on the cooling system by squeezing the bulb acompar'atively few number of times. The cooling system of a; newly manufactured internal combustion engine should be capable of withstanding approximately sevento eight pounds gauge pressure Without leaking and the cooling system of a used automobile should'be capable of withstanding five pounds pressure without leaking. If eitherofsuch cooling sy s term or auxiliary accessory attachments' were found to leak at these pressures they would be found to operate inefiiciently, owing to the fact that they would lose a sufficient'amount of th'e coolant to cause the engine tooverheat. I An ov erf heated engine block'may expand beyond its normal limit of expansion causing it to crack or otherwise rupture, and producing anadditional leak in the cooling system and a greater loss. Again if a slight pressure is subjected bythe detector, the seal of the w'aterfin the 'pumpfof an engine may show a leak due to. the wear of the seal or a poor'fit inthe bearings and'the' sealfof a new pump which would not ordinarilyfbejfound or expected in a new car.

If a leak occurs in the cooling system iwhen pressure is supplied thereto the handlBllldffthe pressure gauge will immediately fall when the ing theengine when it is warm and running.

4 operator stops pumping, which indicates that there is a leak in the cooling system. By inspection of the whole of the cooling system the operator may see the coolant flowing from the leak if it is sufficiently large to emit a stream of the coolant or if small it will ordinarily wet the area around the leak, thus enabling the operator to readily locate and repair the same. If the in- ;dicator 3!! falls and no leak i can ber-detected and the operator is assuredthat the external portion of the system is tight it is quite likely that the leak in the cooling system is into the cylinders of the engine by reason of a faulty gasket. This may be further checked by testing the engine while it is cold and not running and again test- Such a leak may occur while the engine is not operating but stop when the engine is operating and has expanded sufficiently to stop the leak.

The ordinary leaks of a cooling system are usually around the hose connections, in the radi- 'ator or the gasket between the block and the engine head,which leaks can readily-be seen by the operator when pressure is applied to thesys tem. L J {1:

In order to prevent the operaton'from' applying apressurethatis too high-for the coolingsys tem'the Quinnsafety valve 42 is' comiected to the fittin'g through a fourth opening 43 and comprises a housing 44' having a'threaded nipple for connecting to the bore 13 to the chamber-'inthe housing which'is closed at its other end' byJthe plate 45-held in position by thepeened edges 46 V of the housing 44. The inner surfa'ce of 'the'clo sure plate is provided with a valve seat member 41 "arranged to receive the valvemember 48 which-is secured to the outer end of the hollow piston 49 operable within the-housing chamber. The plate 45, the valve seat and the valveimem ber 48 have-aligned openings concentric with the piston49 and open the bore of the-"latter-"to atmosphere; The piston- 45 {is provided 'with an external shoulder 50 arranged to --receive'fone end of the coil spring 5|, the other endof which is initially compressed against-the inner end wall of the'chamber inthe housing 44;- Acoil spring' 52 is compressed withinthe hollow piston49arid engages thevalvemember 48 and thevalve mem' ber 53 which engages the concentric annular valve seat 54 onthe inner end of the hollow-piston member; This Quinns'afety valve is known in the art and can be set to open when subjected to a predetermined pressure and allowstheair to escape from the bore |3=through thefopen ing 43; The pressure is exerted on the valve-'53, lifting the latter from its seat54-by furthr'jcom pressing the spring 52; The valve spring 52 may be calibrated to; release a pressure'-g'reater*than five toten pounds persquarefinchand 'tlius pre vent the operator from applying anexorbitant pressure on the cooling system. The'Qu i'n ri' safety valve will also admit air to the bore l3 throughthe opening 43 if the latter isf 'sub-jected tea vacuum suificiently less to permit" the atmos phericpressure acting upon the interior offthe piston 49' to compress the 1 sprlng' 5l and-admit air between the valve 4 8 and the valve seat 413 does not represent a very'largevolumeand is quickly compressed by a few strokes of the bulb pump 3| to obtain the pressure required on the system. This simple and eflicient apparatus enables the operator to locate a leak before it has had an opportunity to cause any damage and thus avoid the loss of material, equipment and labor.

I claim:

1. In a leak detector for a closed and filled thermosyphon liquid cooling system for automobiles and the like the combination of a bulb pump having valved inlet and outlet openings, a pressure gauge connected to the outlet opening, and a flexible hose for connecting the outlet opening to a closed liquid cooling system for applying a static pressure on the liquid coolant in the system.

2. In a leak detector for a closed and filled liquid cooling system of an internal combustion engine the combination of an air pump, a fitting having a chamber with four openings, a pressure reading device connected to one opening of the fitting, a check valve connected to the second opening of the fitting, means for connecting the air pump to the check valve to supply air under pressure to the fitting, a, pressure release valve arranged to be adjusted to a predetermined pressure and connected to the third opening of the fitting, and a flexible hose connected to the fourth opening of the fitting and arranged for connection directly to the liquid cooling system of the engine for applying a static pressure on the liquid coolant in the system.

3. In a leak detector for a closed and filled circulatory liquid system the combination of an air pump, a fitting having a chamber with a plurality of openings, means for connecting the air pump to an opening of the fitting, a safety valve connected to a second opening of the fitting for releasing pressures above a predetermined amount, and a flexible hoseconnected to a third opening of the fitting and arranged to supply the air under pressure from the fitting directly to the closed liquid cooling system for applying a static pressure on the liquid in the system.

BELDEN H. EATON.

REFERENCES CITED The following references are of record in the 

